Insulating bushing



Oct. 1, 1929. "A; HALLER 1,730,136

INSULATING BUSHING Filed Feb.l27, 192a Patented Oct. 1, 1929 UNITED STATES PATENT OFFICE ARNOLD HALLER, OF BADEN, SWITZERLAND, ASSIGNOR TO AKTIENGESELLSCHAFT BROWN BOVERI & CIE., OF BADEN, SWITZERLAND, A JOINT-STOCK COMPANY OF SWITZERLAND INSULATING BUSHING Application filed February 27, 1926, Serial This invention relates to construction of electrical insulating devices, particularly insulators of the type known as leadingthrough bushings.

The general object of the invention is the provision of a construction which lends itself to economical and expeditious manufacture and which is particularly effective in avoiding glow discharges at the junction of the insulator and its retaining mounting.

Other objects will be pointed out or indicated hereinafter or obvious to one skilled in the art from the present disclosure.

In the drawing forming a part of this specification I show two embodiments for purpose of illustration, but the claims are not to be construed as limited to only these forms. In the drawing,

Fig. l is a part elevational view, partly in section, of a leading-through insulator embodying the invention, and

Fig. 2 is a similar illustration of another embodiment.

Let it be understood that in the drawing the character 0 designates the body of an insulating bushing and b designates the metallic mounting in which it is retained, being secured thereto in any appropriate fashion, as by means of cement b. The dimensions of the body are such that it may slip into the mounting when the latter is in the form of a continuous annular sleeve or hoop. The mounting and bushing may thus be formed complete and in finished condition before assembling. The bushing is provided with encircling grooves a properly spaced to come at the margins of the mounting sleeve. After the bushing has been secured in the mounting, these grooves are filled, wholly or partly, with electrical conducting material which is arranged in contact with the edge portions of the sleeve. This filling may be a conductive cement or paint, or a metal deposited by spraying or otherwise. In Fig. 1 is shown a plastic filling d, and in Fig. 2 a band of metal 6 which is spun or crimped into the groove and fixed in conductive contact with the edges of the mounting sleeve. By thus extending the conductive material from the mounting into the body of the insulator, the forming of No. 91,007, and in Germany March 2, 1925.

glow discharges about the latter is reduced. The arrangement also tends to form a more secure mechanical connection of the insulator in the mounting. An advantage of int-- portance resides in the fact that special trim= ming or fitting of the insulator or mounting is rendered unnecessary in event one or the other varies somewhat from the intended dimensions or contour.

lVhat I claim is 1. Insulator construction comprising an insulator having peripheral depressions formed therein, a mounting encompassing the insulator between the depressions, and conductive material connected externally to the margins of the mounting and moulded into said depressions about the insulator.

2. In combination, an insulator bushing, means fitted about and providing a mounting" for said bushing, said bushing being provided with an exterior annular groove disposed beyond said mounting means and in'proximity to an edge thereof, and conductive means disposed in said groove and extending outwardly beyond said bushing over and in sealing relation with respect to the juncture between the latter and said mounting means and in contacting engagement with said edge.

In testimony whereof I have hereunto subscribed my name at Zurich, Switzerland on the 3rd day of February, A. D. 1926.

ARNOLD HALLER. 

